1. Field
This invention relates to laminate structures particularly adapted for packaging a multitude of products.
2. Description of the Prior Art
U.S. Pat. No. 3,949,114 discloses polymeric laminates containing an oxygen barrier layer of a hydrolyzed olefin-vinyl ester copolymer, e.g. vinyl acetate-ethylene for packaging foodstuffs. Generally, a heat sealable layer and a substrate layer sandwich the olefin-vinyl ester polymeric film to form the laminate.
U.S. Pat. No. 3,923,757 discloses the use of terpolymers of ethylene-vinyl acetate-vinyl alcohol as an adhesive for binding an aromatic polycarbonate of the type formed by reacting Bis-Phenol A and phosgene gas.
U.S. Pat. No. 3,595,740 discloses an oxygen barrier film comprising an inner barrier layer of a melt extrudable hydrolyzed ethylene-vinyl acetate copolymer, an outer layer of a thermoplastic polymer and a heat sealing layer of an ethylene polymer or copolymer. These particular films are adapted for packaging food and are alleged to have significant advantages over packaging laminate films of regenerated cellulose coated with saran or biaxially oriented polyethylene terephthalate films coated with saran and thereafter either laminated or coated with ethylene polymers and copolymers.
U.S. Pat. No. 3,420,679 discloses a laminated film for food packaging which comprises a saran layer and polycarbonate layer. The polycarbonate layer is provided to give strength to the laminate and saran gives oxygen and moisture impermeability.
U.S. Pat No. 3,956,544 discloses a tubular mold having resistance to stretch and having resistence to oxygen and moisture vapor transmission having, as major plies, a polypropylene and cellophane ply coated on each side with saran and these coated plies bonded together with an adhesive. These laminate films were alleged to have excellent characteristics for the processing of cheese.
U.S. Pat. No. 3,917,894 discloses a film particularly adapted for the manufacture of sausage casings and having oxygen and moisture barrier properties. The film comprises a regenerated cellulose film coated with an epoxy-substituted poly-secondary amine resin bonded thereto. Optionally, a top coat is applied to the epoxy-substituted poly-secondary amine resin and such top coats include printing inks, vinyl chloride, alkyd resins, acrylic and methacrylic acid esters, and so forth.
Polyalkylene carbonates formed by reacting for example, ethylene and propylene oxide with carbon dioxide in the presence of a catalyst, have been developed in recent years. Typically, these polyalkylene carbonates have been used as molding compositions. Examples of the polycarbonates and methods for their manufacture are shown in U.S. Pat. Nos. 3,585,168; 3,699.079; 3,748,345; 3,900,424 and 3,953,383.